Water-tube boiler



Patented Apr. 10, 1928.

UNITED STTES PATENT once.

WILHELM HOFF, OF KIEL, GERMANY, ASSIGNOR TO FRIED. KBUPP GERMANIA-WEIR/FT AKTIENGESELLSCHAFT,

OF KIEL-G-AARDEN, GERMANY.

WATER-TUBE BOILER.

Application filed February 13, 1925, Serial No. 8,392, and. in GermanyMarch 6, 1924.

The invention relates to a high pressure water tube boiler, consistingof at least an upper and a lower drum and a bundle of water tubesconnecting them, .the upper drum being protected from the direct attackof the heating gases by a protecting shell arranged concentrically tothe drum at a certain distance therefrom. This shell is formed in aknown manner 01 metal strips with half round. recesses for the tubes.

The purpose of the invention is to provide a simple and suitable supportfor this protecting shell. This purpose is attained according to theinvention by supporting the metal strips upon straps runningtransversely with respect to the drum, the being suspended at both sidesof the drum and the metal strips lying free upon them.

In the drawing is illustrated an embodiment of the subject-matter of theinvention by way of example,

Fig. 1 showing a cross section through tl e boiler,

Fig. 2 showing a section through the upper drum in enlarged scale,

Figs. 3 and 4 showing views from below. of the shell, With differentarrangements of the straps, fixing the shells,

Figs. 5 and 6 showing details.

The water tube boiler consists of an upper drum A and a lower drum Bconnected to one another by the tubes C. The upper drum A is surroundedat its lower side exposed to the fire, by a shell D consisting mannersaccording to the arrangement ot the water tubes. Figs. 3 and 4-illustrate two arrangements, the straps of Fig. 3 extendingperpendicularly with relation to the drum axis, while, as in Fig. 4 thewater tubes are staggered with relation to each other the straps lextend in an oblique direction with relation to the drum axis and aresuperimposed inthis case diagonally in pairs.

In order to attain an absolutely gas-tight connection between the sheetmetal strips, their edges may be formed in various ways. Figs. 5 and 6show two examples therefor. According to Fig. 5 the edges ot the stripscl are tapered at about said tapered surfaces engaging each other.According to Fig. 6 the edges are shouldered. at (Z and overlap eachother.

In assembling the shell the single strips are inserted between the tubesin upright position and then turned 90. The shell may be removed in asimilar manner, without any alteration as to the rest.

I claim:

1. In a water tube boiler comprising upper and lower drums, water tubes.connecting said drums, and a protecting shell arranged concentricallybelow said upper drum consisting of longitudinally running stripsprovided with recesses for the Water tubes, supporting means for saidshell comprising straps running transversely of said shell and suspendedat both sides of the drum, said strips lying tree upon said straps.

2. A boiler according to claim 1 in which said straps are arrangeddiagonally with respect to the axis of the drum andsupt-irimposedcrosswise in pairs.

The foregoin specification signed Hamburg, Germany, this 27th dayotJannary, 1925.

WILHELM HOPE.

